Climate and Biomes

Global climate patterns generated by variation in solar radiation and atmospheric circulation cells (Chapter 2 of the textbook) provide a basis for understanding the geographic distribution of biomes (Chapter 3). The transition from the wet tropics to the seasonal temperate biomes seen in Figure 3.5A in your textbook results in large part from the Hadley cells (see Figure 2.7 below). Ascending air in the atmosphere generates high amounts of precipitation of the tropics, while the descending air at the northern and southern edges creates dry, hot desert zones. Atmospheric scientists have noted a shift in Hadley cell boundaries over the past several decades (Heffernan 2016). The cause for the observed shift is uncertain but anthropogenic caused climate change is predicted to cause greater expansion of Hadley cells over the next century.

 

 

Question 1. How would you expect the area and geographic locations of the tropical rainforest, tropical seasonal forest, and desert biomes to change if the Hadley cells expanded north and south?

Question 2. Projections for the movement of the Hadley cells suggest an expansion rate of around 0.8° latitude per decade (Lucas et al. 2014). If this rate of Hadley cell movement in the Northern Hemisphere continues, how much farther north, in degrees latitude, would you expect the desert biome to occur by 2080? (you can use a calculator but show your calculations below, i.e., what numbers are you using and what operations—multiplication, division, addition, subtraction—are you performing?)

Question 3. The following climate data are for three different locations along a north to south latitudinal transect (at roughly the same longitude) across Colorado and New Mexico. Graph the data as climate diagrams (month on X-axis, Temperature on left-hand Y-axis, and Precipitation on the right-hand Y-axis). Make one graph for each location and label each axis.